Question about Robin the Frog

Recently I watched the first 2 Muppet fairy tale specials, Hey Cinderella (the most bizarre Muppet program I've ever seen!) and The Frog Prince.
For those of you who have seen The Frog Prince, you know that Robin got his start as a young and adventurous prince, before running into Taminella and being turned into a frog.
By the end of the special he turns into a prince again, but this is where I start to get confused...How did Robin become a frog again?
Did he just run into Taminella again or what?

The Muppets have never had a continuity between productions. Storylines of each production never match up properly. It's like Scooter. In the Muppet Movie, he was said to have joined the Muppets with the Electric Mayhem, as their road manager. But then in the Muppet Show, he came in as a new kid asking for a job. Same thing with this: there's no real explanation. The writers just liked the frog version of Robin and decided to start using him later.